Stackable container and apparatus for its manufacture



July 23, 1968 G. W. BROWN STACKABLE CONTAINER AND APPARATUS FOR ITS MANUFACTURE Filed June 27, 1966 FIG. 7

FIG. 6

INVENTQR. S QAYLORD W. BROWN ATTORNEYS United States Patent 3,393,826 STACKABLE CONTAINER AND APPARATUS FOR ITS MANUFACTURE Gaylord W. Brown, Beaverton, Mich., assignor to Brown Machine Company of Michigan, Inc., Beaverton, Mich.,

a corporation of Michigan Filed June 27, 1966, Ser. No. 560,533 4 Claims. (Cl. 220-97) ABSTRACT OF THE DISCLOSURE A stackable container having an annular wall tapering downwardly toward a closed end and being deformed at its closed end to form a projection having a support shelf for the lower end of a similar container, the projection being formed by side walls having upper portions which are arcuate radially and axially and which merge with lower, parallel sides of less width than the width of the shelf so as to preclude sticking of containers within each other due to nesting of the support shelves.

This invention relates to stackable or nestable containers and apparatus for their manufacture, and more particularly the invention relates to the manufacture of molded plastic containers provided with means :for preventing undue telescoping of the containers when one is inserted into another and thereby enabling a plurality of containers to be arranged in stacked or nested condition without sticking to one another.

Coin operated beverage dispensing machines conventionally make use of plastic cups or container which are supported in stacks and from which individual cups may be withdrawn by automatic means. Such cups conventionally have beaded or rolled rims which are utilized in the unstacking operation, so it is necessary that the rims of adjacent containers be maintained in spaced apart relation and that the stacked cups be readily separable. Separation of the rims of adjacent cups and prevention of sticking has been accomplished heretofore by the provision of an inwardly extending annular shelf or ledge located usually adjacent the closed end or bottom of each container in a position to engage the bottom of another container nested within the first container. Ledges or shelves of this type reduce the capacity of the containers.

An object of this invention is to provide an improved stackable container.

Another object of the invention is to provide a stackable container having a plurality of inwardly projecting abutments or supports for engaging the bottom of a nested container and wherein the abutments serve not only to prevent sticking of nested containers but also rigidify the closed end of the container.

A further object of the invention is to provide a stackable container of the character referred to and in which the means for supporting a nested container does not materially reduce the capacity of the container.

Another object of the invention is to provide improved molding apparatus for forming containers of the class described.

Other objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawing, in which:

FIGURE 1 is an elevational view of two nested containers constructed in accordance with the invention with part of the outer container broken away for clarity;

FIGURE 2 is a top plan view of a container;

FIGURE 3 is an enlarged, fragmentary, vertical sectional view through the side and bottom walls of the container;

FIGURE 4 is a sectional view taken on the line 4-4 of FIGURE 3;

FIGURE 5 is an enlarged, elevational view of a portion of the container wall as viewed in the direction of the arrow a in FIGURE 4;

FIGURE 6 is a fragmentary, sectional view through a mold adapted to form containers of the kind shown in FIGURES 1-5;

FIGURE 7 is a top plan view of the mold; and

FIGURE 8 is a fragmentary, elevational view illustrating a modified form of container.

A container constructed in accordance with the invention may be molded from any one of a number of suitable kinds of plastic material such as polyethylene, polystyrene, polypropylene, or the like, and comprises an annular side wall 1 of generally cylindrical, downwardly tapering configuration terminating at one end in a bottom or closure wall 2, the container being open at its other end. Preferably, the open end of the wall 1 is provided with an outwardly rolled head or rim 3.

Within the container and adjacent its bottom wall 2 is a plurality of supports or abutments 4, each of which has a Hat, upper, substantially radially extending wall or shelf, 5 and a flat, substantially vertical or axially extending inner wall or web 6 to which are joined opposed side walls 7 and 8 which, in turn, are joined to the annular wall 1. The annular wall and the bottom wall 2 are deformed inwardly to form the support 4. The walls 7 and 8 are arcuate both radially and axially and have upper portions 9 and 10, respectively, which diverge upwardly and which terminate at their lower ends in wall portions 11 and 12, which are substantially vertical but converge inwardly of the container. The construction of the several wall portions of the support 4 is such that, from outside the container, each support forms a socket 13 having a substantially tulip-shaped appearance, as is shown in FIGURE 5. The shape of the socket is such that the circumferential width of the upper wall 5 is greater than the corresponding dimension between the inner edges of the wall portions 11 and 12. As a result, the support 4 of one container cannot be received by the socket 13 of the container nested therein.

In the containers shown in FIGURES l and 2, there are three identical supports 4 spaced uniformly about the circumference of the container. As many supports 4 as are desired may be provided, however, and FIGURE 8 discloses a container having a large number of such supports. Regardless of the number of supports provided in any container, the walls of each support are joined to the annular wall 1 and to the bottom wall 2 so as to rigidify the closed end of the container. The wall construction of each abutment 4 provides an exceptionally strong support so as to preclude its being deformed or broken by a nested container, and each abutment projects sufliciently far inwardly of its container that the flat wall 5 provides a sufficiently large supporting area to preclude its being imbedded in the bottom of a nested container which might be formed of plastic foam.

A container according to the invention may be formed in a conventional mold 14 comprising a die body or block 15 in which is a cavity 16 having a side wall 17 shaped to complement the wall 1 and having a bottom 18 corresponding to the container bottom wall. Passages 19 in the body 15 communicate with the cavity 16 and may be connected to a source of suction so as to evacuate the cavity 16 during the molding operation, whereupon a suitably heated sheet of plastic material will be drawn into the cavity and take the shape of the walls thereof to form the container.

The abuments 4 are formed in the container during the molding process by means ofpins or plugs 20 driven into sockets 21 located at the juncture of the walls 17 and 18 and spaced uniformly circumferentially about the bottom wall. Each pin has a flat upper surface 22, a flattened rear or outer surface 23 which bears against the wall 17, a flattened inner surface 24 facing into the cavity 16, and opposite side surfaces 25 and 26 having portions conforming to the corresponding portions of the abutment walls 7 and 8. Thus, the upper side edges of the sides 25 and 26 diverge upwardly. As a result, removal of the [formed container from the mold necessitates flexing of the abutment wall portions 11 and 12 in order to remove the pins 20 from the sockets 13.

Although only three pins 20 are disclosed in FIGURES 6 and 7, as many such pins as are desired may be included.

This disclosure is representative of a presently preferred embodiment of container and molding apparatus but is intended to be illustrative rather than definitive of the invention. The invention is defined in the claims.

What'is claimed is:

.1. A stackable container having an annular wall tapering downwardly from an open end to a closure wall at its lower end, said annular wall and said closure wall being deformed inwardly to form a projection having a support shelf for the closed end of a similar container, said projection having side walls whose upper portions are arcuate radially and axially of said container and 4 merge at their upper ends with said shelf, said projection having also lower side wall portions which parallel one another and merge with said upper portions and with said closure wall, said shelf having a greater circumferential width than the circumferential distance between said parallel side wall portions.

2. The construction set forth in claim 1 wherein there are a plurality of said projections spaced circumferentially of said container.

3. The construction set forth in claim 2 wherein said projections are three in number.

4. The construction set forth in claim 1 including an inner, substantially axially extending wall joined to said shelf and to said closure wall and joined to the upper and lower portions of said side walls of said projection.

References Cited UNITED STATES PATENTS 2,854,790 10/ 1958 Hartung. 3,083,888 4/1963 Miller 229-1.5 3,262,626 7/1966 Davis 22097 X FOREIGN PATENTS 254,306 10/ 1964 Australia.

THERON E. CONDON, Primary Examiner.

GEORGE E. LOWRANCE, Assistant Examiner. 

